Method of and apparatus for applying slurries to structural surfaces



SLURRIES TO STRUCTURAL SURFACES METHOD 0F' AND APPARATUS FOR APPLYING Patented Apr. 18, 1950 ori-ICE METHOD OF AND APPARATUS FOR AP- PLYING SLURRIES T STRUCTURAL SURFACES Samuel Clipson, London, England Application February 4, 1948, Serial No. 6,233 In Great Britain July 15, 1946 Section 1, Public Law 690, August 8, 1946 Patent expires July 15, 1966 3 Claims. (Cl. 117-104) This invention is -concerned with the application to structural surfaces, such as ceilings and Walls, of slurries of plaster, cement, mortar and the like.

In accordance with the invention the slurry is mechanically applied by a method which consists in supplying the slurry under pressure along a barrel to the vicinity of an end nozzle thereon affording an abruptly restricted outlet, and in subjecting the slurry in that vicinity to the action of a stream of pressure air or gas to compact and densify the slurry before it leaves the said nozzle outlet.

Apparatus for practising the method comprises a barrel having at one end an inlet for the supply of slurry under pressure and at the other end a discharge nozzle with an abruptly restricted outlet, and means manually adjustable axially of the barrel for introducing pressure air or gas into the barrel in advance of the said abruptly restricted nozzle outlet.

The slurry may be delivered to the gun from any suitable source through a flexible line, and the pressure air or gas supplied to the interior of the gun may also be obtained from any convenient source of supply through a llexible line.

By way of example one form of gun in accordance with the invention is illustrated in sectional elevation by the single figure of the accompanying drawing to which reference will now be made.

I denotes the barrel of the gun in the form of a bent tube the ends of which are externally screw-threaded at .2 and 3. The barrel is equipped with a handle or stock 4 adjacent to which is a trigger pivoted to the barrel at 6 and having its upper end connected by links 1, 1 with a butteriiy valve 8 for regulating the supply of slurry through the barrel. The trigger is urged away from the handle 4 by a spring 8 surrounding a pin 9a projecting from the handle.

Threaded on the end 2 of the barrel I is a nozzle member I0 having an interchangeable nozzle I I having a sharply restricted outlet, whilst threaded on the end 3 is a coupling nut I2 by means of which and an adaptor I3 the barrel I can be connected to -a flexible line I3a leading from a source of slurry supply.

The barrel I has a rearward tubular extension I4 terminating at its rear end in a screw-threaded gland I -5 for a gland nut I6 with the interposition of a packing Il. A tube I8 is slidable in the extension I4 and in the gland and gland nut. Its forward end projects into the barrel I at an adjustable distance from the nozzle II and its rear end is equipped with a cock or valve I9 operable by a handle 20. The cock or valve is connectable, by a flexible line not shown, with any suitable source of supply of pressure air or gas.

In the operation of the gun pressure air or gas is admitted via the tube I8 into the front part of the barrel I under control of the cock I9, where it acts on the slurry supplied under pressure to, the barrel under control of the trigger-actuatedbutterfly valve 8. The slurry is compacted or densied in the front portion of the barrel between the outlet end of the tube I8 and the sharply restricted outlet of the nozzle II and is discharged, by the pressure air or gas, through the said nozzle outlet on to the Wall or surface to which the gun is directed.

The distance of the outlet end of the tube I8 from the nozzle II is easily and instantly adjustable by sliding the tube forward or backward, to obtain the best results depending on the viscosity of the slurry and the available air or gas pressure.

As shown in the drawing the end of the tube terminates in the accumulating chamber 2I of the barre1 I at a distance in advance of the baille wall IIa of the nozzle I I and the abruptly restricted outlet I Ib therein which is not less than twice the diameter of the accumulating chamber whereby mass movement of the compacted 0r densifled slurry is effected under the air or gas pressure. The gland nut I6 serves to lock the pressure tube I8 in an adjusted position.v

By means of the gun it is possible to apply slurries rapidly to structural surfaces and to build up the coating to -any desired thickness.

After operation and in order to prevent slurry setting in the barrel of the gun and the slurry line, the nozzle II may be temporarily closed by any flat surface while pressure air or gas is supplied for a short time through the tube I8 so as to blow back the slurry out of the barrel and slurry line.

If desired a trowel or guide may be combined with the gun to keep the nozzle 'II at a constant distance from the surface being treated.

Reference is made to my copending application Serial Number 775,556, led September 22, 1947, for Smoothing or nishing trowels for information as to the type of trowel used in the method of my invention, and to my copending application Serial Number 775,555, filed September 22, 1947, for Compositions for surfacing walls, ceilings and the like for a disclosure of the composition and method of finishing surfaces according to my in-- vention.

It is to be understood that modlflcations may be made within the scope of the invention as defined by the claims that follow.

I claim: Y y 1. The method of mechanically applying com- 4 c the supply of compacted or densied slurry under pressure and at the other end a discharge nozzle having an internally screw-threaded orifice therein extending on an axis centrally of said pacted anddensiified slurryi-,to structuralfsurfacesa--g barrels4 aV substantially cylindricaligmenbr exwhich consists' in accumulating 'masses\fof-com' pacted and densifled slurry in a connedrspaceand subjecting the accumulated masses of slurry fr to agitated movement and so forcingttieaccumu-:w

ternally screw-threaded Vto enga'ge'ethe internal screw threads in said orifice, said member terminating in abrupt plane surfaces at each end thereof extending substantially normal to the axis lated masses of slurry in an .glabruptgernanneryaogof ;said,.,barre1;ss aidinner abrupt surface constithrough an orice to eiect aV spattering action on the surface being treated.

2. A portable spray gun for applyingwom#v pacted and densied slurry to structurali surfaces tuting a balilieiwallgI-nnd a pressure tube terminating in an outlet extending in a plane substantially parallelto'the said bafe wall of said member and displacedftherefromjo allow accumulation of comprising a barrel having at one endian Vinletr .compactedaand densied slurry intermediate the for the supply of compacted or densifiedslurry, bafliewall o-f said member and the end of said under pressure and at the other enda dischargiejf prefssuiejube'f whereby the masses of slurry can nozzle with Ian abruptly restricted outletfan ac' chamber .of vthe barrel at a4 position Ain.advance of said abruptly restrictedoutlet'notiless-than at lealsttwioe r ther-'diameter iof Y said accumulating be 'successively spattered upon a surface to be treatedibylsudden pressure ejection through said Y Y SAMUELcursori.- REEERENGES Cursif@Y The following references are of record in-the--if means in said, adjusted position rfor; discharging compactedr-densied :slurry from said accumu-i lating chamber.

3. A portable spraygunfor applying-,compacted s or ydensied sluiry :to structural .surfaces com-59.30 v1.2,30526192r2' prisng ga. barrelhaving at. one end` an1inlet fon-n..

UNITEIjgs'rlrrns'1:Plrrmrrsf-i Number-.1: p Name.A Date 2,259,215, Sclflelllelze.V

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